London has been battered by 50mph winds that have felled trees and caused travel chaos. Powerful gusts swept across the capital as the Met Office issued a yellow "be aware" weather alert for most of the country.

Some UK airlines could face huge compensation bills from passengers following a European court ruling on flight delays.

A number of airlines, including British Airways and easyJet, had challenged a 2009 ruling that passengers on flights to and from Europe should be compensated if they are delayed for more than three hours.

However, the European Court of Justice (ECJ) in Luxembourg confirmed the 2009 ruling after the airlines had challenged the UK's Civil Aviation Authority (CAA) over the matter.

There will still be exceptional circumstances where compensation will not have to be paid, such as industrial action and extreme weather. But there are a number of compensation cases that have been put on hold since 2009 for which carriers might now have to pay out.

The judgment was welcomed by the CAA, which said the situation was now clearer for passengers.

CAA regulatory policy director Iain Osborne said: "Every year around 200 million passengers travel on two million flights to and from the UK, with the vast majority experiencing no problems. However, when something does go wrong, there are regulations in place to protect travellers and the CAA is ready to ensure companies abide by them.

"The judgment from the Court of Justice of the European Union offers much-needed clarity for passengers, the airline industry and the CAA about when compensation must be paid following delays."

A British Airways spokesman said: "We are aware of the ruling and will continue to comply with the regulations."

Travel company Tui, which was involved in the legal challenge, said: "We note today's ruling by the ECJ.

"We are committed to treating our customers fairly and will continue to work with the European institutions to ensure that the underlying legislation is revised such that it strikes the right balance for passengers and airlines."